The invention relates to a closure cover of synthetic or plastic material including a cover cap having several resilient fingers arranged on the lower side thereof. Each finger has a stop area or retaining portion located at a predetermined distance from the lower side of the cover cap for extending through a support opening.
According to the current state of the art, a closure cover of the type is already known that comprises three resilient fingers distributed over its periphery (German Printed Specification 34 42 109). The resilient fingers are relatively rigid due to a supplementary support and the rest area is, moreover, of compact design. Because of this circumstance, the sealing effect of this known closure cover proves to be inadequate.
Likewise, other known closure covers (German Petty Patent 19 59 426, British Patent 734 857, and German Printed Specification 23 14 021) are similarly designed and are, consequently, not capable of sealing a support opening with the maximum tightness.
Consequently, there is posed, for the present invention, the problem of creating a sealing plug or closure cover of the type initially mentioned, by which one can obtain an improved seal effect despite simple construction.